The present invention relates to firearms of the type known as revolvers, and it relates more particularly to means for accurately indexing the cartridge-chamber cylinder thereof for successively aligning each chamber with the barrel.
A long-standing and well recognized problem in obtaining consistently accurate alignment of all of the chambers in the cylinder of a revolver is the need for extremely close manufacturing tolerances in various operations, such as machining the ratchet teeth on the cylinder by which it is rotated or forming the engagement surfaces on the cylinder hand or pawl that engages the teeth. Since even close tolerances can not invariably assure the accuracy required of quality revolvers, skilled hand-filing of the parts is usually necessary in the manufacture of a first-rate revolver. This obviously involves considerable expense.
It is an object of the present invention to provide a reliable system for indexing the cylinder without resorting to the skilled techniques of the gunsmith. Various proposals have been made in attempts to increase the accuracy with which the cylinder is indexed in order to align each chamber in the cylinder with the barrel, but when large-scale production is required, cost is an important factor and accuracy of alignment has usually suffered.
Some revolvers that are made on a large scale index well and are reliable as long as the trigger is pulled rapidly or the hammer cocked smartly, but if the shooter pulls the trigger slowly in order to improve his aim, the cylinder stop or lock may not engage properly before the cartridge is discharged, resulting in misalignment of the chamber with the barrel at the instant of discharge. It will be appreciated, moreover, that if a revolver is carefully designed and made in order to decrease the force required to pull the trigger in double-action and to make the trigger-pull as uniform as possible throughout the entire stroke of the trigger, smoother action and better aim can be achieved. Discriminating revolver users, such as policemen, will then tend to fire such guns more often in double-action, as opposed to the usual method, where greater accuracy of aim is desired, of first cocking the hammer by means of the cocking piece and then firing in single-action by pulling the trigger. Consequently, in quality revolvers of this type, it becomes mandatory that the cylinder stop or lock, as it is called hereinafter, be fully engaged with a cylinder notch before the hammer is released, so that accurate alignment of the cartridge with the barrel is assured when it is discharged.